The Alvin Olympian Comfort Drafting Height Chair is designed for comfort and durability. This chair is tailor-made for larger-sized or taller people. The ergonomically contoured molded foam seat is extra thick with a waterfall edge for maximum comfort. Pneumatic height control raises and lowers the chair quickly. The included armrests are height and width adjustable. Additional features include dual-wheel casters and a 26" diameter polished aluminum base. It includes CK49 height extension kit and adjusts from 24" to 28".